The gears in machine gear systems are often linked or meshed together in very close tolerances that create a tight fit between individual gears. The tight tolerances help to minimize wear on gears by reducing the amount of free space between gear teeth. Free space allows gears to travel or rotate without resistance leading to a “hammer” effect when the gears finally do encounter resistance in the form of another gear.
While tight tolerances between gears reduce wear on the gears, it also makes it more difficult to remove gears for maintenance or replacement. Normally, the most frequent way of removing gears is to apply a simple pulling force to a gear puller attached to one or more gears or a gear set. The application of this force can lead to damage to the gears if not applied precisely and can also lead to injury to the persons carrying out the pulling operation.
Because the amount of force required to remove a gear or gear system can be considerable, it is sometimes necessary to add a secondary force to the puller. Often this secondary force is the application of vibration. U.S. Pat. No. 2,648,374 to Qualen discloses a machine that uses vibration to help remove tires from tire rims. An air hammer is raised and lowered by alternately applying and removing air pressure to a piston that is pushed up to strike against a head holding a tire and tire rim. The vibration caused by the piston helps to shake the tire off the tire rim. U.S. Pat. No. 3,224,086 to Balamuth discloses the use of a vibrator to aid in the insertion of one rod or gear into a bore in a larger rod or encasement.
U.S. Pat. No. 5,644,987 to Koura discloses a printing press with an apparatus for attaching and detaching bearings for the press cylinder. In one embodiment, a vibrator is used to beat against the bearing in the direction of extraction to help remove the bearing from the press. Similarly, U.S. Pat. No. 6,839,947 to Dudeck discloses a power hammer puller in which a cylindrical tube is attached to a multi-clawed gear puller. The hollow tube holds an air hammer that directs a forceful pulse of air against an opposite end plate. The vibration of the repeated pulses from the air hammer eventually results in pulling the bearing from its housing.
The devices disclosed in the above prior art are related in that the vibration are created by a piston, air hammer, or other device directed along an axis. As such, the efficiency of each of the devices increases in direct proportion to the space that is available to increase the length of the vibrational axis. However, none of the disclosed devices provide for situations in which a limited amount of space is available to generate a forceful axial vibration. In addition, none of the cited prior art discloses the use of vibrators that do not cause an axial vibration using a moving piston or other item.
Thus, there is a need in the field for a device and method for removing tightly fitting gears from there housings when only a limited amount of space is available.